Rubber stamp



May 6, 1969 TAKAJl FUNAHASHI 3,442,209

RUBBER STAMP Filed March 24, 1967 United States Patent US. Cl. 101-327 6 Claims ABSTRACT OF THE DISCLOSURE A multi-color rubber stamp which comprises a plurality of receiving frames corresponding in number to the colors to be applied and containing rubber letter blocks extending through elongated slots at the bottom faces of the receiving frames and ink absorbers surmounting the rubber blocks. The receiving frames are supported in separate chambers formed in a frame casing, the latter being detachably mounted within a machine frame, which in turn is slidably mounted for vertical movement in a sleeve member between a first position in which the letter blocks are retracted and a second position in which the letter blocks project below the lower edges of the sleeve member. An external frame is connected to the machine frame and slidably receives the sleeve member with the interposition of a spring between the external frame and sleeve member, urging the external frame and machine frame to its retracted position.

This invention relates to a rubber stamp and more particularly to a rubber stamp which is most suitably adapted for multi-color stamping practice.

The conventional rubber stamps have been generally made either by simply engraving a series of letters on a rubber stamp block or by adhering on a stamp base a rubber letter block prepared by pressing non-vulcanized rubber to a die on which a series of letters are engraved and curing same therein. These conventional stamps, therefore, involve much trouble in practical use because they must be used after inking the letter-engraved surface by pushing it on the ink-impregnated stamp pad each time it is used. Further, in case a series of letters are arranged in plural rows, the color of the letters printed is restricted to only one color of ink used, and it is impossible to attain a multi-colored printing. To overcome such inconveniences, the present inventor has previously developed an improved rubber stamp which has eliminated any necessity of applying ink to the engraved letter surface each time it is used, by making the letter block from a porous rubber block which can retain ink. But this improved stamp was not free from such disadvantages that the color of the letters in each row is confined to the color of the retained ink while also it was impossible to replace the letter block.

The present invention is designed to eliminate these defects and to provide a further improved rubber stamp comprising a casing including a plurality of partitions defining a number of separate chambers in the casing, a plurality of receiving frames corresponding to the number of colors to be applied, said frames being supported in respective chambers in said casing, a letter block in each said frame extending downwardly therefrom, an ink absorber surmounting each letter block in each frame, a machine frame detachably receiving said casing, a sleeve member receiving said machine frame for relative vertical sliding movement between first and second positions, said sleeve member including a depending wall which in said first position extends to a level below the letter blocks in said frames whereas in said second position said letter blocks extend below the level of said wall of said sleeve member, an external frame slidably mounted on said sleeve member and engaging said machine frame to displace the same between said first and second position, and spring means between said sleeve member and said external frame urging the latter to a raised position on said sleeve member corresponding to said first position of said machine frame, said external frame being depresible on said sleeve member against the action of said spring means to lower the machine frame to said second position.

The invention will be described hereinbelow with reference to the accompanying drawing, in which:

FIG. 1 is a front elevation view, partly cut away, of a rubber stamp according to the present invention; and

FIG. 2 is an exploded perspective view, with parts cut away, of the composing members.

Referring to the drawing, numeral 1 designates supporting frames which are made of stainless steel or other similar material and are of a square trough-like configuration having a substantially U-shaped section when viewed sidewise, said frames being provided in a number corresponding to the desired number of colors to be applied. At the bottom of each of said supporting frames 1 is provided an elongated slot 2. Numeral 3 denotes rubber letter blocks made of a porous rubber material composed of butadiene-acrylonitrile rubber, and these letter blocks 3 are installed in parallel to each other within the respective supporting frames 1 in such manner that the engraved surfaces 3' of the letters to be printed are externally exposed from the elongated slots 2. It will also be seen that in each supporting frame 1, there is provided, in contact with the upper surface of the rubber letter block 3, an ink absorber 4 made of porous synthetic resin, such as polyvinyl formal resin or other suitable porous materials. Numeral 5 is a frame casing made of acryl-butadiene-styrene copolymer (ABS) or the like. Said casing 5 has its interior divided by partition walls to form a plurality of (four in the embodiment shown in the drawing) partitioned chambers 6 in each of which is detachably mounted a supporting frame 1. Numeral 7 is a machine frame made of stainless steel or the like, provided with integral, upwardly projecting elongated plates 8. Said machine frame 7 detachably receives therein said casing 5 through theengaging sections 5', 7' at both opposed external sides of easing 5 and frame 7 respectively. On said machine frame 7 is also vertically slidably mounted a sleeve member 9 made of stainless steel or similar material, said sleeve member 9 having an opening 10 so formed as to permit said elongated plates 8, of said machine frame 7 to protrude therethrough. At the opposed edges of said opening 10 are formed erect guide plates 11, for correctly adjusting the vertical sliding movement of the sleevemember 9. Numeral 12 denotes an external frame made of such material as acrylbutadiene-styrene copolymer (ABS) which is mounted over the sleeve member 9 through the medium of springs 16, to be described later. Said frame 12 has placed thereon a cover 15 which is also made of such material as acrylbutadiene-styrene copolymer (ABS). On the upper inner face at both sides of said external frame 12 are provided subsidiary horizontal plate members 13 having holes 13 into which are inserted lugs 8, formed at the uppermost edges of the elongated plates 8, of said machine frame 7 thereby detachably connecting the machine frame 7 and the external frame 12. There is also formed a small space 14 between the bottom end of the external frame 12 and the sleeve member 9 to permit vertical sliding movement of the sleeve member 9. It will be appreciated that said springs 16, are disposed along the guide plate portions 11, of the sleeve member 9 between the upper face of the sleeve member 9 and the subsidiary plate members 13, of the external frame 12 so that the springs will elastically press against the sleeve member 9 to keep its edges 9 usually extended slightly beyond the engraved surfaces 3 of the rubber letter blocks 3. The springs are composed of an elastic plastic material having elastic arms 16 bifurcated from the center of the base 16'. Numeral 6' indicates ink feeding ports formed in the frame casing 5 for feeding ink into the partitioned chambers 6 separately.

For practising the present invention as described above, ink of various colors, such as red, yellow, blue, green, etc., is first introduced in each ink absorber 4 provided in each row of letter blocks and then the device is pressed against a paper while holding the cover with one hand. Since the machine frame 7 having detachably mounted therein the frame casing 5 accommodating in its partitioned chambers 6, the rubber letter blocks 3 and the ink absorbers 4 through the medium of supporting frames 1 are engaged with the external frame 12 by means of elongated plates 8, of the frame 7, it will be appreciated that the sleeve member 9 in which the machine frame 7 is vertically slidably mounted is pushed up against the force of springs 16, causing the machine frame 7 to descend along with the external frame 12 while maintaining a condition in which the edges 9 of the sleeve member 9 normally extended slightly beyond the surfaces 3 of the rubber letter blocks 3 are abutted against the paper. This in turn permits abutment against the paper of the letter-engraved surfaces 3' of the rubber letter blocks 3 placed in the partitioned chambers 6 of the frame casing 5 fitted in said machine frame 7. Thus, with the rubber letter blocks 3 being wet with ink supplied through the innumerable continuous pores from the ink absorbers 4 lodged in the partioned chambers 6 on the back of said letter blocks, it is possible to attain a precise application on the paper of desired letters each having a different color according to the color of ink in each blotter 4. After application, the pressure against the paper is released and the device is raised, whereby the sleeve member 9 returns to its original position in accordance with expansion of the springs 16, and the surfaces 3 of the rubber letter blocks 3 covered with ink are returned into a position where, since the edges 9' of the sleeve member 9 are now in an extended state, the ink-covered surfaces are kept safe from being contacted with other objects and soiling them. Thus, even if the printing operation is repeatedly conducted, different colors of ink for each row are not mixed since the rubber letter blocks 3 are detachably fitted within several partitioned chambers 6 formed in the frame casing 5 mounted in the machine frame 7 through the medium of the supporting frames 1 each having an elongated slot in the bottom face thereof. Further, it is possible to easily disassemble and replace the rubber letter blocks when so desired and to supply ink to the ink absorbers 4 in case they are short of ink, thus assuring very convenient use of the device.

As will be apparent from the above explanation given in relation to a preferred embodiment, the present invention provides a very useful rubber stamp in which a plurality of rubber letter blocks 3 having continuous pores are supported in parallel rows in a plurality of receiving frames in accordance with the desired letters or original manuscript, whereby it is possible to easily and precisely conduct the repeated printing on paper with more than two different colors by ink of different colors supplied from each ink absorber disposed on top of each letter block. Further, inks of different colors for respective rows are free from being mixed, and it is also possible to easily disassemble and replace the rubber letter blocks to readily supply ink as occasion demands. Thus, the present invention has opened up a new sphere in the field of rubber stamps and its industrial significance is apparent.

What is claimed is:

1. A multi-color rubber stamp comprising a casing including a plurality of partions defining a number of separate chambers in the casing, a plurality of receiving frames corresponding to the number of colors to be applied, said frames being supported in respective chambers in said casing, a letter block in each said frame extending downwardly therefrom, an ink absorber surmounting each letter block in each frame, a machine frame detachably receiving said casing, a sleeve member receiving said machine frame for relative vertical sliding movement between first and second positions, said sleeve member including a depending wall which in said first position extends to a level below the letter blocks in said frames whereas in said second position said letter blocks extend below the level of said wall of said sleeve member, an external frame slidably mounted on said sleeve member and engaging said machine frame to displace the same between said first and second positions, and spring means between said sleeve member and said external frame urging the latter to a raised position on said sleeve member corresponding to said first position of said machine frame, said external frame being depressible on said sleeve member against the action of said spring means to lower the machine frame to said second position.

2. A stamp as claimed in claim 1 wherein said external frame includes horizontal plate members and said machine frame includes upstanding plates detachbly connected to said horizontal plate members and acted on thereby to move the machine frame between said first and second positions.

3. A stamp as claimed in claim 2 wherein said sleeve member includes upstanding guide plates extending in spaced, confronting relation with the external frame, said spring means comprising a spring member between each guide plate and said external frame, said spring member acting on said sleeve member and a horizontal plate member of said external frame.

4. A stamp as claimed in claim 1 wherein said casing has ink feeding ports leading to the absorbers in the receiving frames in said chambers.

5. A stamp as claimed in claim 1 wherein said casing and machine frame include confronting depending walls which are detachably engaged thereby permitting removal of the casing with the machine frame supported in the sleeve member and attached to the external frame.

6. A stamp as claimed in claim 1 wherein each receiving frame has a lower end With a slot therein, the letter block in each frame being supported therein with a lower printing surface projecting through said slot.

References Cited UNITED STATES PATENTS 796,132 8/1905 Laycock 101-380 2,427,765 9/1947 Chollar 101327 2,900,902 8/1959 Becker 101-327 ROBERT E. PULFREY, Primary Examiner.

FRED A. WINANS, Assistant Examiner.

U.S. Cl. X.R. 10l380 

